PSLE Jade has a triangular piece of paper GHJ with HG = HJ, ∠GHJ = 84° and ∠JKK = 65°. GKJ and HKJ are straight lines. She folded it along the line KL as shown.
- Find ∠m.
- Find ∠n.
(a)
Length of GH = Length of HJ
Triangle GHJ is an isosceles triangle.
∠HJG
= (180° - 84°) ÷ 2
= 96° ÷ 2
= 48° (Isosceles triangle)
∠m
= 180° - 65° - 48°
= 67° (Angles sum of triangle)
(b)
∠HGJ = ∠HJG = 48°
∠p
= 180° - 65° - 65°
= 50° (Angles on a straight line)
∠n
= 180° - 48° - 50°
= 82° (Angles sum of triangle)
Answer(s): (a) 67°; (b) 82°